A peek into the world of endangered beneficial bugs

Missing in action

A girl stares at a Tussar silkworm at an insect exhibition at GKVK on Sunday. (Below) A collection of insects with electrodes and cameras attached displayed at the exhibition. The setup reflects studies in international institutes where insects are used t

A six-spotted beetle, which was once profuse in the city, but has since gone extinct in urban environments, on display at an insect exhibition at GKVK on Sunday.

A collection of insects with electrodes and cameras attached is displayed at an insect exhibition at GKVK on Sunday. The setup reflects studies in International Institutes where insects are used to serve as drones for surveillance and rescue work. DH phot

A collection of insects with electrodes and cameras attached is displayed at an insect exhibition at GKVK on Sunday. The setup reflects studies in International Institutes where insects are used to serve as drones for surveillance and rescue work. DH phot

Urbanisation has pushed a swathe of beneficial insect populations out of the city limits, impacting the ecological balance of the metropolis, said senior entomologists of the University of Agricultural Sciences at GKVK.

Professor K Chandrasekhar, who until Saturday was the head of the university’s Entomology Department, explained that while GKVK has been conducting a study on insect population for the past 15 years, that much of data is still far from interpretation.

“We can nevertheless determine that insect populations in the city have suffered a dramatic decline based on the absence of many such species from urban landscapes,” he said.

He was speaking on Sunday on the sidelines of a three-day exhibition on insects intended to educate the general public on the value of insects to an ecosystem.

Among the missing species is the large, painted grasshopper, a three-inch-long insect whose primary diet is milkweed, a toxic flowering weed commonly found in vacant land.

“Because this grasshopper is now extinct in the city, we are finding that there is no organism to break down these weeds,” Chandrashekar said.

Another victim has been the six-spotted beetle, a large two-inch-long predatory insect, which was instrumental in controlling smaller insects. “Thirty years ago, this beetle was common in the city,” he added.

According to GKVK estimations, the city has seen a decline in 41% of total species over the past 10 years, with a significant percentage (46%) being pollinators, which are critical for the development of flora and food plants (84% of crops are pollination dependent). Also, 68% of caddisflies have gone extinct as have 53% of butterflies, and 49% of beetles.

One cause for the decline in the insect population is light pollution at night. “This upsets the natural circadian rhythm of insects,” explained Prof S Ramani, a senior entomologist.

Bug drones

The exhibit which assembled over 500 species of insects (the majority from Bengaluru area) also included a sample of beetles and flying insects outfitted with robotic gear, which GKVK staff said was part of ongoing research in several western countries to use flying insects as mini-drones for surveillance and rescue work.

“Electrodes are attached to the wings and legs to manipulate the nervous system of the creature. A micro camera helps the human controller to guide the insect to specific locations. Trials are being carried out in international institutes to train these insects to seek out CO2 emissions. The idea is to get the insects to enter collapsed buildings to search for human survivors who will be exhaling CO2,” said a GKVK staffer.